Heat exchanger plate interleaving at acute angles - in the manner of a pitched roof

ABSTRACT

The invention relates to a heat exchanger plate with a triangular profile, wherein the triangles connect each plate together with a base line and the triangles of the two adjacent plates point towards each other with their tips and stand on the base line of the other plate. In a second profile shape, the triangles are replaced by a profile shape that resembles a house with a pitched roof. The profile elements which protrude into the area of the “condensate tray” can be shortened by A h in the area where the condensate forms to improve condensate drainage. This reduces the adhesion forces, as a result of which the condensate can drain away better. The profiles can also have a zigzag shape (seen in the direction of flow).

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a U.S. National Phase Application under 35 U.S.C 371 of International Application No. PCT/DE2019/000210, filed on Aug. 3, 2019, which claims the benefit of German Patent Application No. 10 2018 006 461.2, filed on Aug. 10, 2018. The entire disclosures of the above applications are incorporated herein by reference.

FIELD

This invention relates to a heat exchanger plate.

BACKGROUND

This section provides background information related to the present disclosure which is not necessarily prior art.

A heat exchanger having a zigzag profile is known from utility model DE 296 20 248 and patent document DE 196 35 552 (FIG. 19a ).

As is well known, the heat exchange area can be increased by a small profile width (s). This however reaches limits in the deep-drawing process.

SUMMARY

This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features.

This problem can be solved by plugging together two different profiles (1, 2) (FIG. 1). The base profile of the invention is designed such that two (predominantly equilateral) triangles (D1 and D2) (pointing in one direction) are interconnected by a planar base line (B) (FIG. 1).

The triangles (D1, D2) in the lower plate are laterally offset in relation to the triangles (D3, D4) in the upper plate such that they can be plugged into each other (FIG. 1, 2). The points of the triangles (D1, D2, as well as D3, D4) of the two plates (1, 2) face each other, wherein the triangle point (3, 4) of a plate (B) stands on the base line of the other plate. The profiles are fixed and held relative to each other in this manner. The advantage compared to the zigzag profile is improved deep drawing capacity (due to the baseline (B)).

The thermotechnical advantage compared to prior art are short heat flow paths (a) between triangle edges that run parallel (FIGS. 3 and 19 b). The included angle (α) can have any desired size: 0°<α<180°, but it should be an acute angle wherever possible to avoid a too high number of plates (expensive!).

The angle α becomes rather small in the novel triangular profile if the profile height (h) is great and the profile width (s) is at the same time small. This results in a very narrow flow cross section (F) in the region of the acute angle (FIG. 3). Due to higher sliding friction on the wall in relation to the narrow flow cross section, the flow rate and thus the heat transfer coefficient drop in this region of a narrow flow cross section; pressure loss increases.

To solve this problem, the triangle (1, 2) is replaced by a pointed roof shape (5, 6) in another novel profile variant (FIGS. 4a, b , 5).

The thermotechnical advantage is that the triangle (2) (having longer heat flow paths) is converted into a narrow zone with parallel flanks (right and left “house wall”) and provided with a “pointed roof” (8) (FIG. 4a ). At the same time, the heat exchange area is increased compared to the triangle.

In the “pointed roof,” an even angle distribution of 3×60° rather than 1×90° and 2×45° can be advantageous (flow in the angular region)—but it somewhat decreases the heat exchange area (detail Y, FIGS. 5, 6).

To improve the overlap of the profiles standing on top of each other, either the overlap width (b) can be increased by increasing the angle (β) from 45° (detail X) to 60° up to 90°, for example (FIGS. 5 a, b, c), or a rectangular overlap area (13) (detail Z, FIG. 14a ) is provided. All forms of overlap should advantageously extend over a short length (I) only (viewed in the flow direction).

The parallel flanks of the pointed roof profile can be made slightly conical (5 b, 6 b)(FIG. 7) for better removal from the mold during deep drawing.

The success of deep drawing can be improved by rounding or flattening the corners, which means that thinning and holes in the deep drawing material can largely be prevented.

Good condensate drain in the heat exchanger profile is advantageous for improving the heat recovery rate and pressure loss and for reducing the risk of freezing. To this end, the profile according to the invention can be modified such that the profile members (y) with their points facing down do not project all the way into the “condensate tray” (x), but their points (y) remain above the “condensate tray” (x) by shortening the profile height by Δh (FIG. 8).

In prior art, it is more difficult for the condensate to drain off in the region of the acute angle α (FIG. 19a ) of the zigzag profile (greater adhesion forces).

In heat exchangers in which the profile is arranged vertically, it is useful to provide a “condensate tray” on both sides (that is, at the “top” and the “bottom”) (FIGS. 10 and 11).

Therefore, the shortening by Δ h is also applied to the profile point (z) pointing up (FIG. 10).

The associated reduction in heat exchange area is smaller than the gain in effective heat exchange area due to better condensate drainage and heat exchange area becoming available. This applies to a design in which the Δ h shortening of the profile points is limited to the section at the end of the heat exchanger (in the flow direction of the condensing air flow) only, in which section condensation can be expected (based on calculation or testing).

Another increase in heat exchange area can be achieved if the shortened point is converted into a rectangle (7 a, 8 a) (FIGS. 9 to 11).

An overlap area (w) is required at a required distance C to the adjacent plate for locking the profiled plates (FIGS. 10 and 11). The two profile members (u1, u2) adjacent to the overlap area (w) are advantageously shortened (e.g. by Δh) to avoid having to increase the deep-drawing height (due to the overlap area (w)). The overlap area (w) can also be limited to a very short section. The profile variants with the shortened profile height (Δh) are useful, in addition to improved condensate drain, for increasing the distance (h) (distance of the profiled plates), allowing a reduction of the number of plates for a heat exchanger (economic advantage).

The length of the flow thread and thus the dwell time and heat exchanging time can be increased by means of a zigzag (11) or sine wave (12) shaped course of the profile structure (12, 13), when viewed in the flow direction, which results in an improved heat exchanging capacity. The heat exchange area increases by about 6% due to the zigzag structure (FIG. 12), with area losses in the edge region (R) (FIG. 12b ) already taken into account.

A zigzag-shaped profile course (11) (viewed in the flow direction) increases the heat transfer coefficient by turbulences. The profiles lying on top of each other run synchronously (5, 5 a) (FIG. 14). The zigzag-shaped profile course viewed in the flow direction swirls the flow section E located at greater profile depth (FIGS. 5, 12 a), particularly at great profile heights, which swirling is caused by frequent deflection at the corners (FIG. 12b ).

The advantage of swirling can also be achieved by V-shaped protrusions (14) (FIG. 15). The V-shaped protrusions (14) run synchronously in all plates lying on top of each other.

The V-shaped protrusion (14) can also be installed in a zigzag-shaped profile course (FIG. 17).

The V-shaped protrusions can also have an arc-shaped (15) design (U shape) (FIG. 16).

The distribution of the media in the profiles (channel distributor) is shown in FIGS. 18a and 18 b.

The foregoing description of the embodiment has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure. 

1-7. (canceled)
 8. A heat exchanger having multiple heat exchanger plates stacked on top of each other and having a triangular profile, wherein the triangles of each heat exchanger plate are interconnected by a base line and the points of the triangles of two adjacent heat exchanger plates face each other and stand up on the base line of the respective other heat exchanger plate, wherein the heat exchanger plates standing on top of each other and plugged into each other have an overlap area relative to each other.
 9. The heat exchanger according to claim 8, wherein the corners and points of the profiles are rounded or flattened and the parallel flanks of the pointed roof profile are made slightly conical.
 10. The heat exchanger according to claim 8, wherein the overlap area of the heat exchanger plates only extends over a short length.
 11. The heat exchanger according to claim 8, wherein the profile structure of the heat exchanger plates, viewed in the flow direction, takes a zigzag or sine wave course, wherein the profile structure is synchronous in all heat exchanger plates lying on top of each other.
 12. The heat exchanger according to claim 8, wherein the profile structure, viewed in the flow direction, has recurring V-shaped protrusions, both for an otherwise straight profile course and for a zigzag profile, wherein the V-shaped protrusions can be rounded on the edges and have a U shape.
 13. A heat exchanger having multiple heat exchanger plates stacked on top of each other, wherein the heat exchanger plates have profile shapes which are designed like a house with a pointed roof, the points of the profile shapes facing up and down, wherein the points of two heat exchanger plates plugged into each other face in opposite directions and in doing so stand on the base lines of the other heat exchanger plate, wherein adjacent house shapes with a pointed roof are interconnected by a baseline in such a manner that a rectangle facing downwards or upwards and having beveled corners is created and the heat exchanger plates standing on top of each other and plugged into each other comprise an overlap area relative to each other, wherein in order to improve the overlap area, the angle of the beveled corners of the rectangles can be increased from an angle β=45° to any desired angle within the limits of 45°<β≤90°, or wherein a rectangular overlap area is provided on the beveled corners.
 14. The heat exchanger according to claim 13, wherein for improving condensate drain, the profile points do not abut the adjacent heat exchanger plate, at least in the section of the heat exchanger in which condensate formation can be expected, but have a distance Δh providing sufficient spacing from the adjacent heat exchanger plate, whereby space is provided for improving the condensate drain to the condensate draining on the adjacent heat exchanger plate in the “condensate tray”.
 15. The heat exchanger according to claim 14, wherein an overlap area is provided at a distance for interlocking the heat exchanger plates if there is a Ah distance and on both sides.
 16. The heat exchanger according to claim 14, wherein the overlap area only extends over a short section of the heat exchanger, and the profile members respectively adjacent to the overlap area are shortened.
 17. A heat exchanger comprising: a plurality of heat exchanger plates, wherein each heat exchanger plate comprises a profile shape that repeats in a series; wherein the profile shape comprises a triangular proximal portion, a rectangular medial portion and a triangular distal portion, wherein a point of the triangular distal portion defines a distal end of the profile shape; wherein each profile shape is separated from an adjacent profile shape by a lateral space and wherein each profile shape is interconnected to an adjacent profile shape by a base line; wherein the plurality of heat exchanger plates are arranged in pairs of adjacent heat exchanger plates; wherein the distal ends of the profile shapes of a pair of adjacent heat exchanger plates are nested within the lateral spaces of the respective other heat exchanger plate of the pair of heat exchanger plates and are disposed near the base line of the respective other heat exchanger plate of the pair of heat exchanger plates; wherein the pair of heat exchanger plates define an overlap area relative to one another; and wherein an included angle (β) of the triangular proximal portion is 45°<β≤90°.
 18. The heat exchanger according to claim 17, wherein the distal ends of the profile shapes are spaced a distance Δh from the base line of the respective other heat exchanger plate of the pair of heat exchanger plates.
 19. The heat exchanger according to claim 17, wherein the distal ends of the profile shapes abut the base line of the respective other heat exchanger plate of the pair of heat exchanger plates.
 20. The heat exchanger according to claim 17, wherein the plurality of heat exchanger plates, when viewed in a flow direction, extend along a zigzag or sine wave course. 